tbuckley/cabot-search huggingface dataset:
Abstract P2097: Ablation Of Fibroblast Human Antigen R (HuR) Mitigates Cardiac Fibrosis
Authors: Sarojini Singh, Mallikarjun Patil, Praveen K Dubey, Tousif Sultan, Prachi Umbarkar, qinkun zhang, Hind Lal, Steven pogwizd, Jianyi J Zhang, Prasanna Krishnamurthy
Journal: Circulation Research (2023)

Background: Cardiac fibrosis is a common pathology associated with various heart diseases and is attributed to the activation of resident fibroblasts. Limiting fibroblast-to-myofibroblast differentiation and proliferation could be a pragmatic approach to mitigate adverse cardiac outcomes. Recent studies have shown that RNA-binding proteins are critical in the post-transcriptional regulation of fibroblast-to-myofibroblast differentiation. Human antigen R (HuR), an RNA-binding protein, modulates post-transcriptional gene expression in various pathophysiology, including heart diseases. However, the direct role of cardiac myofibroblast HuR is largely unknown. Methods and Results: To investigate the role of myofibroblast-specific HuR in cardiac fibrosis, we generated a tamoxifen-inducible periostin-Cre-driven myofibroblast-specific HuR knockout (KO) mouse. Control and KO mice were subjected to transverse aortic constriction (TAC), and cardiac functions were assessed by echocardiography. Histological and morphometric analyses were used to evaluate cardiac fibrosis and remodeling eight weeks post-injury. Our results demonstrated that myofibroblast-specific deletion of HuR limited cardiac fibrosis and preserved cardiac functions in HuR knockout mice compared to the control group. Further, the knockdown of HuR in human cardiac fibroblasts suppressed myofibroblast differentiation after treatment with TGF-β1 (10 ng/ml), as observed by a decrease in cell migration and production of extracellular matrix-associated molecules. Interestingly, an in vivo BrdU labeling assay showed a reduction in myofibroblast proliferation in KO mice subjected to TAC compared to the control. Further investigation confirmed that HuR regulates cyclin D1 mRNA stability in TGF-β1-stimulated cardiac fibroblasts, and deletion of HuR restricts myofibroblast proliferation in a cyclin D1-dependent manner. Conclusion: Our findings indicate that HuR plays a central role in the post-transcriptional regulation of cardiac fibrosis and could be a potential therapeutic target for clinical applications.
Abstract P2065: Mice Under Transverse Aortic Constriction And Treated With Sodium Oxalate May Develop Cardiac Dysfunction
Authors: Amanda A Silva, Juliana R Marques, Bruno Nascimento-Carvalho, Leandro E Souza, Maikon B Silva, Acaris Benetti, Dunia Waked, Mariana M Veras, Maria C Irigoyen
Journal: Circulation Research (2023)

Background: Experimental models are important for studying the mechanisms of cardiovascular disease. The transverse aortic constriction model (TAC) is among the most used in the literature for the study of cardiac hypertrophy. The soluble sodium oxalate (OXA) model generates renal injury but is also associated with cardiac hypertrophy through hypertensive-like lesions. There is little information in the literature on direct hemodynamic recording in both models mentioned, as well as there is no data on the changes caused by the association of these two models. Therefore, our objective is to evaluate whether TAC associated with OXA gavage could be a new model of cardiac dysfunction. Methods and Results: Male C57BL mice were randomized as follows: SHAM animals that received gavage with vehicle or OXA solution, and animals submitted to TAC and gavage with vehicle or OXA solution. Echocardiography and metabolic cage assessment were used to quantify cardiac and renal function. Direct blood pressure (BP) recording was also performed to assess baroreflex sensitivity and histological analysis. The TAC+OXA group had the highest BP values (mean BP:SHAM:100±5.0 vs. TAC+OXA:132±4.8mmHg, p&lt;0.01), the highest pulmonary congestion index, an increase in the double product, an important reduction in autonomic modulation (AM), heart rate variability (HRV) (SD-PI: SHAM+OXA:12.5±1.8 vs. TAC+OXA:2.8±0.2ms, p&lt;0.01) and alpha index (SHAM:3.6±1.0 vs. TAC+OXA:0.6±0.1, p=0.04). The TAC group showed the greatest weight of the ventricles and the greatest increase in blood pressure variability (DP-SBP). The SHAM+OXA group showed an increase in AM and HRV. The three groups showed a significant reduction in reflex tachycardia. Conclusion: TAC surgery provided cardiac hypertrophy, reduction in reflex tachycardia and changes in autonomic modulation. In the absence of TAC, the treatment with OXA for 15 days increased autonomic modulation. TAC surgery in conjunction with OXA gavage caused greater cardiac dysfunction.
Abstract P1039: Soluble Extracellular Matrix Protein Induces Senescence In Aortic Valve Interstitial Cells To Up-regulate Valvular Osteogenic Activity
Authors: Qingzhou Yao, Lihua Ao, David Fullerton, Xianzhong Meng
Journal: Circulation Research (2023)

Background: Calcific aortic valve disease (CAVD) is the most prevalent heart valve disease in the elderly, and elevated osteogenic activity of aortic valve interstitial cells (AVICs) play a critical role in CAVD progression to severe aortic valve stenosis. While soluble extracellular matrix (ECM) proteins, including biglycan and matrilin 2, have been found to up-regulate the osteogenic activity in human AVICs, the mechanism underlying the cellular and molecular mechanisms remain unclear. As greater densities of senescent AVICs were observed in human calcified aortic valves, we tested the hypothesis that soluble ECM protein induces senescence in AVICs to up-regulate valvular osteogenic activity. Methods and Results: Human AVICs were isolated from normal and CAVD aortic valves. Levels of P16 and P21 were assessed by immunoblotting, and senescent changes is identified using senescence-associated β-galactosidase (SA-β-gal) staining. AVICs from diseased valves displayed higher levels of P16 and P21, greater SA-β-gal staining and active calcium deposition. Soluble matrilin 2 (2.0 μg/ml) up-regulated the expression of P16 and P21, and enhanced SA-β-gal staining in normal AVICs, leading to greater calcium deposition. Further, knockdown of P16 markedly reduced calcium deposition in AVICs exposed to soluble matrilin 2. The impact of soluble matrlin 2 is associated with activation of the M6PR-ERK1/2 pathway. Blocking or knockdown of M6PR (M6P, 10 mM or siRNA, 1.0 nM), or inhibition of ERK1/2 (PD98059, 25 μM) attenuated the effect of soluble matrilin 2 on AVIC senescence and resultant up-regulation of osteogenic activity. Conclusion: AVICs from aortic valves of patients with CAVD have higher levels of senescence activity. Soluble matrilin 2, via the M6PR-ERK1/2 pathway, induces AVIC senescence to promote the osteogenic activity. Targeting the D-M6PR-ERK1/2 pathway may suppress AVIC senescence and attenuate aortic valve calcification associated with CAVD progression.
Abstract P3127: Atrial Myocytes From Patients With Paroxysmal Atrial Fibrillation Show A Higher Predisposition To Arrhythmogenic Action Potential Alternans
Authors: Funsho E Fakuade, Vanessa Steckmeister, Fitzwilliam Seibertz, Fleur E Mason, Katharine M Dibb, Ingo Kutschka, Niels Voigt
Journal: Circulation Research (2023)

Background: Alternans, the periodic beat-to-beat alternation in electrical and calcium signaling of a cardiac myocyte stimulated at a fixed frequency is well documented to be proarrhythmic. Nonetheless, the involvement of alternans in the processes promoting paroxysmal atrial fibrillation (pAF) is unknown. As such, we set out to ascertain if alternans contribute to the arrhythmogenic mechanisms in pAF. Methods: Simultaneous action potentials (patch-clamp) and [Ca 2+ ] i (Fluo3) were recorded in right atrial myocytes obtained from patients with sinus rhythm (Ctl; n=16) and pAF (n=8). AP and CaT alternans were acquired and analyzed using a custom-written software. Results: AP duration was similar between pAF and Ctl groups over different pacing frequencies, exempting electrical remodeling in pAF. A higher incidence of CaT alternans (46% vs 18%; P =0.08) and AP alternans (82% vs 52%; P &lt;0.05) was observed in myocytes from pAF patients compared with Ctl ( Figure A ). Additionally, the minimum frequency at which AP alternans was detected was significantly lower in pAF (2.4 ± 0.8 vs 4.6 ± 0.6 Hz; n/N=9/6 pAF vs 13/12 Ctl; P &lt;0.05; Figure B ). However, the AP restitution was unchanged in Ctl and pAF myocytes ( Figure C ), thus suggesting CaT alternans as the primary driver of AP alternation ( Figure D ). Conclusion: Atrial myocytes from pAF patients exhibit a higher predisposition to cellular alternans that may alter excitation-propagation in the atria and contribute to the arrhythmogenic substrate in these patients.
Abstract P3078: The Stimulator Of Interferon Genes (STING) Modulates Adverse Cardiac Remodeling Induced By Cardiac Pressure Overload: New Role Of Endothelial Cell Sting In Systolic Dysfunction
Authors: Erin Sanders, Noah Wagner, Sasha Smolgovsky, Abraham Bayer, Brandon Theall, Mark Aronovitz, Kuljeet Kaur, Pilar Alcaide
Journal: Circulation Research (2023)

Introduction: Cardiac inflammation is a hallmark of heart failure (HF) defined by T cell infiltration and increased expression of pro-inflammatory cytokines. Type I Interferon (IFN-I), a cytokine induced upon activation of STING, is increased in the heart after myocardial infarction and transverse aortic constriction (TAC). We reported that absence of endothelial cell (EC) STING results in an IFN-I dependent decline in T cell extravasation to inflammatory sites. We hypothesized that STING contributes to adverse cardiac remodeling induced by TAC and EC STING regulates systolic dysfunction through modulating cardiac inflammation. Methods: Male wildtype (WT), STING -/- and inducible EC specific STING -/- mice (Cad5 ERTCre2+/- STING fl/fl treated i.p. with 85mg/kg Tamoxifen), or oil treated and Cre - littermate WT controls were subjected to TAC or Sham surgery. Systolic function by echocardiography and left ventricular (LV) hypertrophy, fibrosis, and capillary density by histology were analyzed four weeks post-surgery and T cell activation was characterized in mediastinal draining lymph nodes (MdLN) by flow cytometry. Results: In contrast to WT, STING -/- mice did not show a decline in ejection fraction (EF). LV hypertrophy was decreased in TAC STING -/- mice compared to TAC WT mice. Isolectin staining showed that capillary density was higher in STING -/- mice in response to TAC as compared to the expected capillary loss observed in WT TAC mice. The frequency of CD4+CD62 lo CD44 hi cells in the MdLN, indicative of effector T cell activation, was decreased in STING -/- mice compared to WT mice in response to TAC. Similar analyses of Cad5 ERTCre2+/- STING fl/fl mice showed that EC STING -/- mice did not show a decline in EF in response to TAC, in contrast to their littermate WT controls. However, no changes were observed in LV hypertrophy, fibrosis or capillary density between groups and activation of MdLN effector T cells was also comparable in both groups. Conclusion: STING contributes to adverse cardiac remodeling induced by TAC. While EC STING contributes to systolic dysfunction through a yet unknown mechanism, STING in other cell compartments contributes to cardiac hypertrophy, capillary density and T cell activation in response to TAC.
Abstract P3094: Cell-autonomous Immune Signaling In Human Cardiac Fibroblasts Modulates Fibrosis
Authors: Indulekha C Pillai, Anisha Latha, Gayathri Vijayakumar
Journal: Circulation Research (2023)

Cardiac fibrosis is the pathophysiological hallmark of injury in an adult heart. Immune response in the injury niche modulates fibrosis. However, how cell-autonomous immune signaling in cardiac fibroblasts modulates fibrosis is unknown. In this report, we demonstrate that cardiac fibroblasts express TLR4 receptors, and inhibition of TLR4 signaling inhibits fibrotic changes such as proliferation and myofibroblast conversion in human cardiac fibroblasts. Using FACS, and single-cell data of cardiac fibroblasts from Colagen1 GFP mouse, we demonstrate that TLR4 is the predominant TLR and approximately 90 % of human cardiac fibroblasts express TLR4 receptors. Using EdU labeling, cardiac fibroblasts taking up EdU have reduced from 91.65 ± 3.89% from control conditions to 71.15 % ± 2.05 % (mean ± SEM, n=3, p&lt; 0.05) in TLR4 inhibited condition. Ki67 staining shows a similar reduction from 93.1 ± 2.34 % to 59.3% ± 3.54%. TLR4 inhibition in TGF-β treated human cardiac fibroblasts reduced the expression of Periostin expression by 2.6 ± 0.58 and Sma1 by 1.46-± 0.18(mean ± SEM, n=3)fold. Further, migration of cardiac fibroblasts demonstrated a 76.3± 10.23 % (mean ± SEM, n=3, p&lt; 0.05) reduction in the presence of TLR4 inhibitor. Transcriptome analysis of TLR4-inhibited cardiac fibroblasts shows downregulation of proliferation-related genes and pathways. Ingenuity pathway analysis (IPA) of differentially expressed genes in TLR4-inhibited TGF-β -treated cells compared to TGF-β alone shows a reduced expression of a subset of target genes of TGF-β signaling. Further, compared to healthy controls, single-cell data of heart failure patients show significant elevation of Histone 3 and Histone 4 in the fibroblast cluster along with chromatin readers, Brd4 and Nox4. Inhibition of TLR4 in human cardiac fibroblasts reduced the expression of Histone 3 and Histone 4, with Nox4 modulating the chromatin architecture required for fibroblast activation. Thus our data demonstrate that cardiac fibroblast act as an immune cell having cell-autonomous immune signaling, regulating fibrotic changes. Ongoing experiments in 3D human cardiac organoid injury models will reveal how TLR4 signaling regulates fibrotic activation of human cardiac fibroblasts in a heterogeneous system.
Abstract P3113: Apyrase But Not Dipyridamole Improves Cardiac Function In Ovariectomized High-fat Diet Mice
Authors: Adnan A Khan, Elizabeth Russ, Ahmed Sohail, Yifan Bu, Eitezaz Mahmood, Ruma Bose, Jessica Cassavaugh, Kamal Khabbaz, Feroze Mahmood, simon robson, Robina Matyal
Journal: Circulation Research (2023)

Objectives: Postmenopausal women with metabolic disease are predisposed to develop cardiovascular disease. Our previous experiments have shown that these women experience purinergic/adenosinergic signaling alteration resulting in diastolic dysfunction. We hypothesize that these signaling alterations are reversible and to demonstrate we used exogenous CD39 agonist (apyrase) and an ENT-1 inhibitor (dipyridamole), in a murine model simulating postmenopausal women. Methods: We fed 23 C57BL/6 female mice a HFD (40% kcal) from 5 weeks of age and performed ovariectomy at 12 weeks. Intraperitoneal (IP) injections were given daily to three groups for 10 days at 28 weeks. The following groups and dosages were used: apyrase (9 mice, 200U/kg), dipyridamole (9 mice, 20mg/kg), and saline (5 mice). At 30 weeks, mice were assessed with an EchoMRI for body composition, and transthoracic echocardiography (TTE) used for evaluation of cardiac function while mice were anesthetized with 2.5% isoflurane. Results: Our apyrase-treated mice, had significantly lowered values in E/E’, E/A, with increased Ejection Fraction and Fraction Shortening when compared to the saline treated groups, analyzed with t-test. Apyrase also had lower body weight, lean mass, fat mass, and heart/body weight percentage, when compared to saline (p&lt;0.05). Dipyridamole had significant increase in LV diastolic volume and IVRT when compared to our saline group. Conclusion: Our findings could suggest that increased ectonucleotidase activity may ameliorate diastolic dysfunction experienced in our murine model. Future studies are needed to confirm its effect in postmenopausal women.
Abstract P2151: A Novel, Micellized Naringenin Nanoparticle Rescues Hemodynamic Function Post-Myocardial Infarction Via MARK4 Inhibition
Authors: Noah Weingarten, Amit Iyengar, Danika Meldrum, Sara Guevara-Plunkett, Jessica Dominic, Ahmad Amirshaghaghi, Daphne Nie, Andrew Belec, Mrinal Patel, Joyce Ho, David A Herbst, Benjamin Lee, Deborah Eaton, Zhiliang Cheng, Andrew Tsourkas, Pavan Atluri
Journal: Circulation Research (2023)

Impaired contractility and associated shock are significant contributors to morbidity after myocardial infarction (MI). Elevated MARK4 activity after MI impairs contractility by increasing α-tubulin detyrosination. As such, we developed a nanoparticle-based therapeutic strategy to enhance myocyte function with a small molecule MARK4 inhibitor (naringenin) and tested its ability to improve myocyte function in a rat model of MI. Naringenin was encapsulated in PEO-PCL to augment bioavailability. Adult Wistar rats underwent thoracotomy and were randomized to receive either: MI + myocardial injection of micellized naringenin (0.3 mg/kg) [MI-Nar], MI + empty micelle [MI-Mic], MI alone [MI-Untreated], or no MI [Sham]. MI was achieved with left anterior descending artery ligation. On pressure-volume hemodynamic assessment 24 hours post-thoracotomy, MI-Nar rats had higher ejection fractions than MI-Mic or MI-Untreated rats (63±3% v. 48±5% vs. 39±4%, p&lt;0.05) and similar levels to Sham rats (61±1%, p=0.97). MI-Nar rats had greater stroke work, and lower end-diastolic pressure and tau than MI-Untreated rats (all p&lt;0.05). Isolated myocytes from infarct border zones had increased contraction and relaxation velocity in MI-Nar versus MI-Untreated rats (both p&lt;0.0001; Fig. 1A, B). Improved function was associated with decreased α-tubulin detyrosination in MI-Nar versus MI-Untreated rats on Western blot (p&lt;0.05; Fig. 1C, D). These data support small molecule inhibition of MARK4 via micellized naringenin as a novel strategy to rescue hemodynamics post-MI by mitigating myocardial α-tubulin detyrosination and enhancing myocyte function.
Abstract P2094: The Regulatory Role Of Sirtuin 6 In Coronary Microcirculation In Hfpef
Authors: Yang Wang, Molly Enrick, James Gadd, Alyssa Clark, Liya Yin
Journal: Circulation Research (2023)

Coronary vasculature is essential to support the supply oxygen and nutrients to the heart and maintain the normal cardiac function. Obstruction of large vessels of coronaries (atherosclerosis) is well studied, but coronary microvascular dysfunction (CMD), which is associated with diabetic cardiomyopathy, Takotsubo cardiomyopathy, andheart failure with preserved ejection fraction (HFpEF), is understudied. CMD is characterized by impaired endothelial-dependent vasodilation, but detailed mechanisms have yet to be elucidated. Sirtuin 6 (Sirt6) has been implicated in obesity, insulin resistance, type 2 diabetes mellitus, and cardiovascular diseases. Sirt6 protects EC from premature senescence, oxidative stress, and atherosclerosis by sustaining high eNOS levels and preserving cell replication. A recent publication showed that overexpressed Sirt 6 in EC mitigated heart failure with preserved ejection fraction (HFpEF) in diabetes. We hypothesize Sirt 6 deficiency causes CMD in HFpEF How Sirt6 regulates coronary microvascular function remains to be determined. Inducible Sirt6 endothelial-specific knockout and wild-type (WT) mice were fed a chow or high fat and sugar (HFHS) diet. Coronary arterioles were isolated, and endothelial-dependent vasodilation (EDD) was assessed using myography (DMT). Echocardiography and treadmill exercise exertion tests were performed to evaluate cardiac function. Myocardial blood flow (MBF) was measured by doppler. Cardiac fibrosis was detected using trichrome staining, and molecular pathways were elucidated via gene and protein analysis. Our preliminary data show that the EDD of coronary arterioles of Sirt6 endothelial-specific knockout treated with HFHS was impaired, and the mediator of coronary vasodilation switched from NO to H 2 O 2 in the Sirt6 knockout mice. Compared to the WT mice, myocardial blood flow and cardiac function were changed in Sirt6 knockout mice. Our data suggest that Sirt6 regulated coronary microvascular function through endothelial cells, and ablation of Sirt6 in endothelial cells caused CMD and diastolic dysfunction, eventually HFpEF. Further genetic profiling will elucidate the pathways and mechanisms converging with Sirt6 to regulate microvascular function in HFpEF.
Abstract P2006: Cardiac Cytoskeleton Sequesters Acetylated Yap In The Cytoplasm To Inhibit Cardiomyocyte Renewal After Myocardial Infarction
Authors: Shijie Liu, Vaibhav Deshmukh, Fansen Meng, Yidan Wang, Yuka Morikawa, Jeffrey Steimle, Rich Gang Li, Jun Wang, James F Martin
Journal: Circulation Research (2023)

The Hippo pathway effector YAP is essential in cardiomyocyte proliferation and heart regeneration. How YAP responds to physiological conditions such as myocardial infarction (MI) is unclear. Here we show YAP transiently localizes to the nucleus of border zone CMs after MI. Nuclear YAP is acetylated by P300/CBP, and SIRTs deacetylation activity is decreased due to metabolic stress resulting from the injury. These mechanisms in conjunction results in increased acetylated YAP accumulation in the cytoplasm. After MI, the cardiac cytoskeleton is stabilized and sequesters cytoplasmic acetylated YAP, which reduces YAP activity and inhibits cardiomyocyte renewal. In a genetically engineered mouse model with a mutation that abolishes YAP acetylation, the mutant heart exhibits improved cardiac regeneration ability compared to the wild-type heart due to increased nuclear YAP localization. Together, we demonstrate that the injury-induced metabolic shift results in YAP acetylation, which translocates YAP to the cytoplasm in a manner independent of the Hippo pathway, and is detrimental to cardiac regeneration after MI.
Abstract P3083: Trim29 Deficiency Ameliorates Viral Myocarditis By Reducing Perk Mediated Er Stress And Ros Responses
Authors: Junying Wang, Wenting Lu, Yong Du, Jerry Zhang, Laurie J Minze, Junji Xing
Journal: Circulation Research (2023)

Infections by viruses including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could cause viral myocarditis. Endoplasmic reticulum (ER) stress is associated with several metabolic diseases such as cardiovascular disease, diabetes and cancer. However, the immune mechanisms of ER stress regulation in controlling the pathogenesis of viral myocarditis are unclear. Here, we found that knockdown or knockout of TRIM29 significantly inhibited PERK (Protein kinase RNA-like endoplasmic reticulum kinase) mediated ER stress and apoptosis induced by cardiotropic viruses CVB3 (coxsackievirus B3) or EMCV (encephalomyocarditis virus) in human and mouse cardiomyocytes. Additionally, TRIM29 deficiency relieved ROS (Reactive oxygen species) mediated STING (Stimulator of interferon genes) inhibition to produce more type I interferon for restricting cardiotropic viruses in cardiomyocytes. Importantly, cardiomyocytes specific TRIM29 deficiency exhibited dramatic protective effects on cardiac damage, cardiac dysfunction, viral replication and promoted survival in CVB3-induced viral myocarditis model in vivo . Mechanistically, TRIM29 was shown to interact with PERK and catalyze SUMOylation for maintaining its stability, thereby promoting PERK mediated ER stress and ROS responses to induce pathogenesis of viral myocarditis. Our results indicate that TRIM29 loss-of-function in cardiomyocytes ameliorates viral myocarditis by reducing PERK mediated ER stress response and unleashing ROS-suppressed interferon response. Our data suggest the TRIM29-PERK axis is a potential therapeutic target for viral myocarditis and other ER stress-associated cardiovascular disease.